National Coral Reef Monitoring Program
Climate Monitoring Brief: STT and STJ
Diver surveying XX reef
NOAA/Atlantic Oceanographic & Meteorological Laboratory (AOML) Coral
Program
University of Miami Cooperative Institute of Marine and
Atmospheric Studies (CIMAS)
N. Besemer, A. Palacio, A. Webb, G. Kolodziej, T.Gill, I. Enochs - January 2024
Mission
The AOML Coral Program tracks the status and trends of coral reef ecosystems of the U.S. Atlantic and Caribbean as part of the National Coral Reef Monitoring Program (NCRMP). This summary brief provides an overview of the most recent climate monitoring efforts in Saint Thomas and Saint John (US Virgin Islands).
Expedition summary
- The NCRMP Atlantic climate monitoring team recently traveled to XX from XX to XX, 2023
- XX different sites were visited by three team members and collaborators completing a total of XX dives.
Data collection summary
Subsurface temperature Subsurface temperature recorders (STRs) were recovered and redeployed at all nine transects, each one composed by four depths (Fig. 1). In total, more than 7.7 million temperature observations were collected from 24 instruments (Table 1)
| Site | 1m | 5m | 15m | 25m | Total |
|---|---|---|---|---|---|
| STT South | 453,593 | 183,211 | 451,119 | 289,775 | 1,377,698 |
| STJ South | 469,774 | 436,645 | 180,320 | 407,891 | 1,494,630 |
| STJ West | NA | 410,823 | 482,659 | 435,436 | 1,328,918 |
| STJ East | NA | 291,654 | 415,524 | 484,125 | 1,191,303 |
| STJ North | NA | 345,430 | 156,514 | 439,660 | 941,604 |
| STT North | NA | NA | 475,215 | 288,161 | 763,376 |
| STT West | NA | NA | 291,082 | 321,330 | 612,412 |
NCRMP Climate fixed sentinel site monitoring: At XX - 5m site, located in XX, short term instruments (XXh) were deployed to monitor daily fluctuations in:
- Current: 303 observations
- pH: 307 observations
- Light: 301 observations
- Carbonate Chemistry: XX samples collected
Habitat persistence: Changes in bioerosion and accretion were monitored:
- Carbonate budget surveys: Benthic cover, sponge, urchin, and parrotfish surveys completed at XX transects
- Bioerosion: XX Bioerosion Monitoring Units (BMUs) collected, XX redeployed
- Calcification: XX Calcification Accretions Units (CAUs) collected, XX redeployed
Figure 1: Study sites and depths in Puerto Rico.
Subsurface temperature
The temperatures that marine organisms experience are a function of local oceanographic conditions and vary with depth. To monitor subsurface temperature, six transects were established around the island. Each transect consists of STRs at four depths (1, 5, 15, 25m; Fig.2). Temperature was measured using SeaBird Electronics Subsurface Temperature Recorders (STR)s that collected data at 5-minute intervals. The instruments are usually swapped every 3 years for data collection but the COVID - 19 pandemic delayed field work in 2020. Local contractors were hired to swap the instruments as travel was not allowed and so gaps exist in the data as not all instruments survived the extended deployment time. The entire record from 2017 to 2023 is shown to aid with comparison.
Figure 2: Temperature conditions at seven transects representing a depth gradient (1m, 5m, 15m and 25m). Data were collected from August 2017 to March 2022. The COVID 19 pandemic caused a significant delay in collection of these instruments and some of them had stopped recording. Contractors were hired to complete the work in 2021 as travel was not allowed. Some instruments survived the entire deployment but others have not.
Mean temperature values were similar among the locations and depths. The lowest temperatures generally occurred in February (mean: 26.5\(^\circ\)C, min: 24.7\(^\circ\)C, max: 28.5\(^\circ\)C) and the highest temperatures in September (mean: 29.4\(^\circ\)C, min: 25.4\(^\circ\)C, max: 32.2\(^\circ\)C).
Diurnal suite deployment
Seawater carbonate chemistry can fluctuate diurnally, due to biological forcing processes such as photosynthesis and respiration, as well as calcification and dissolution. To characterize this, discrete water samples (Fig. 3) were collected at three-hour intervals (n=15) using Subsurface Automatic Samplers (SAS, www.coral.noaa.gov/accrete/sas).
These samples will be analyzed for Total Alkalinity (TA), Dissolved Inorganic Carbon (DIC), and SpectrophotometricpH (SpecpH), which will be used to calculate pCO2 and aragonite saturation state (ΩAragonite). A suite of instrumentswas deployed for a 54-hour period at the La Parguera 5m site. A SeaFET was used to log pH, an EcoPAR measured Photosynthetically Active Radiation (PAR), and a Lowell Tiltmeter measured current speed and direction. Each collected measurements at 15-minute intervals (Fig. 3).
## DateTime pH Temperature
## Min. :2023-07-24 09:00:00 Min. :7.368 Min. :29.38
## 1st Qu.:2023-07-25 04:07:30 1st Qu.:7.767 1st Qu.:29.64
## Median :2023-07-25 23:15:00 Median :7.814 Median :29.70
## Mean :2023-07-25 23:15:00 Mean :7.790 Mean :29.71
## 3rd Qu.:2023-07-26 18:22:30 3rd Qu.:7.870 3rd Qu.:29.84
## Max. :2023-07-27 13:30:00 Max. :7.958 Max. :29.98## DateTime pH Temperature Temp.adj
## Min. :2023-07-24 09:00:00 Min. :7.368 Min. :29.38 Min. :7.599
## 1st Qu.:2023-07-25 04:07:30 1st Qu.:7.767 1st Qu.:29.64 1st Qu.:7.667
## Median :2023-07-25 23:15:00 Median :7.814 Median :29.70 Median :7.682
## Mean :2023-07-25 23:15:00 Mean :7.790 Mean :29.71 Mean :7.686
## 3rd Qu.:2023-07-26 18:22:30 3rd Qu.:7.870 3rd Qu.:29.84 3rd Qu.:7.721
## Max. :2023-07-27 13:30:00 Max. :7.958 Max. :29.98 Max. :7.758## DateTime PAR sd
## Min. :2023-07-24 09:25:48.7 Min. : 0.0343 Min. : 0.00000
## 1st Qu.:2023-07-25 04:12:03.7 1st Qu.: 0.0344 1st Qu.: 0.00001
## Median :2023-07-25 22:58:18.7 Median : 15.1437 Median : 0.04935
## Mean :2023-07-25 22:58:18.7 Mean : 96.7526 Mean : 7.34244
## 3rd Qu.:2023-07-26 17:44:33.7 3rd Qu.:134.0962 3rd Qu.: 1.07443
## Max. :2023-07-27 12:30:48.7 Max. :742.1805 Max. :199.70382## date ws wd
## Min. :2023-07-24 13:15:00 Min. :0.290 Min. : 0.41
## 1st Qu.:2023-07-25 08:07:30 1st Qu.:2.045 1st Qu.: 98.39
## Median :2023-07-26 03:00:00 Median :3.270 Median :210.04
## Mean :2023-07-26 03:00:00 Mean :3.367 Mean :184.89
## 3rd Qu.:2023-07-26 21:52:30 3rd Qu.:4.375 3rd Qu.:266.55
## Max. :2023-07-27 16:45:00 Max. :7.370 Max. :359.64
## DateTime ws.adj
## Min. :2023-07-24 09:15:00 Min. : 29.2
## 1st Qu.:2023-07-25 04:07:30 1st Qu.:205.9
## Median :2023-07-25 23:00:00 Median :329.3
## Mean :2023-07-25 23:00:00 Mean :339.1
## 3rd Qu.:2023-07-26 17:52:30 3rd Qu.:440.6
## Max. :2023-07-27 12:45:00 Max. :742.2
Figure 3: Data from XX diurnal suite monitoring from July 24th to July 27th. Top panel: pH and temperature fromSeaFET. Bottom panel: Photosynthetically Available Radiation (PAR) and current speed from EcoPAR and Tiltmeter. Shading denotes nighttime throughout sequence of the plot. Instruments measured parameters every 15 minutes.
Habitat persistance
Carbonate budget assessments use transect-based surveys to quantify the abundance of carbonate producers (e.g., Corals and Crustose coralline algae), and carbonate bioeroders, (e.g., parrotfish and sea urchins). Abundances are multiplied by taxon-specific rates of carbonate alteration to determine if a reef is in a state of net accretion (habitat growth) or net loss (habitat loss; Fig. 4). At La Parguera, six transects were surveys in 2015, 2017 and 2023 to obtain carbonate budgets. These data show stable carbonate production over the monitoring timepoints. The transect results showed positive carbonate budgets in 2015, 2017 and 2023, which implies that this site supported reef accretion over the past eight years. ADD MORE HERE MAYBE CHAT DIP IN MACRO/MICRO BIOEROSION, INCREASE OF CCA, COOL OUTLIERS?
Figure 4: Total changes in net carbonate production and separated by the functional groups contributing to either calcification or bioerosion. PF represents parrotfish.
Calcification Accretion Units (CAUs) and Bioerosion Monitoring Units (BMUs) were used to investigate the balance between calcification and erosion. CAUs and BMUs were collected and redeployed for the next sampling cycle. CAUs are processed by the NCRMP Pacific Climate group and the data will be available within a year. BMUs will be dried and cleaned using a hydrogen peroxide solution. These samples will be weighed and scanned using a CT scanner and then compared to their pre-scans to quantify bioerosion. Data will be available in a year. Please reference previous datasets for more information.
About the monitoring program
AOML’s climate monitoring is a key part of the National Coral Reef Monitoring Program of NOAA’s Coral Reef Conservation Program (CRCP), providing integrated, consistent, and comparable data across U.S. Managed coral reef ecosystems. CRCP monitoring efforts aim to:
- Document the status of reef species of ecological and economic importance
- Track and assess changes in reef communities in response to environmental stressors or human activities
- Deliver high–quality data, data products, and tools to the coral reef conservation community
Point of Contact
Atlantic Climate team lead: nicole.besemer@noaa.gov
Principal Investigator: ian.enochs@noaa.gov
NCRMP Coordinator: erica.towle@noaa.gov
For more information
Coral Reef Conservation Program: http://coralreef.noaa.gov
NCRMP climate monitoring: https://www.coris.noaa.gov/monitoring/climate.html
NOAA Atlantic Oceanographic and Meteorological Laboratory: http://www.aoml.noaa.gov/
Acknowledgements
These efforts were jointly funded by NOAA’s CRCP project #743 and OAP. We would like to sincerely thank the University of Puerto Rico Mayaguez campus particularly Milton Carlo for all of the mission support we received in La Parguera. We would also like to thank our other collaborators: Staff at Jobos Bay National Marine Estuary, PR Diving Services, Taino Divers and the University of the Virgin Islands for supporting our field efforts.
Our Team
XXX Field Team: XXX
AOMLs NCRMP Atlantic and Caribbean Climate Team: I. Enochs, N. Besemer, A. Palacio-Castro, G. Kolodziej, T. Gill, A.Boyd, M. Jankulak, K. Simmons, A. Webb, B. Chomitz